Pakistan said Friday this week's "unprovoked firing" by India set back the peace process between the two nuclear-armed rivals and warned New Delhi to refrain from any "adventure," saying the army would respond to aggression.

Exchanges of fire are common along the tense and heavily guarded frontier, but this week's flare-up, which left more than 20 people dead, is the most serious violation yet of a 2003 cease-fire agreement.

"We say yes to peace, but we will not accept hegemony of any country," Interior Minister Chaudhry Nisar Khan said after attending a top-level meeting convened by Prime Minister Nawaz Sharif to discuss tensions along the Line of Control that separates Pakistan-controlled Kashmir from Indian-held Kashmir.

Khan said the National Security Committee decided to write a letter to the United Nations about the "unprovoked Indian firing" which began on Sunday as Muslims in the region were preparing to celebrate the Eid al-Adha holiday.

New Delhi has accused Pakistan of starting this week's skirmishes, saying it wants to create a distraction to help separatist militants infiltrate into Indian-controlled Kashmir.

Pakistan has repeatedly denied this, saying it gives only moral and diplomatic support to separatist groups who have been fighting since 1989 for Kashmir's independence or its merger with Pakistan.

The fighting subsided on Friday as Sharif met with advisers and military chiefs to discuss the latest spasm of violence, which killed 13 civilians in Pakistan and eight in Indian-held Kashmir over the past week.

A statement issued by Sharif's office after the meeting said Pakistan was resolved to respond to any attempts to challenge its territorial integrity and sovereignty "with full force" and that its military was "fully prepared to deal with any adversity at our borders."

It said Pakistan had taken steps to improve ties with India, but the sincerity demonstrated by Islamabad was not reciprocated.

The latest fighting began weeks after New Delhi called off foreign secretary-level talks after Pakistan's ambassador met with Kashmiri separatists. The two sides had previously agreed to resume talks in May when Sharif attended the inauguration of Indian Prime Minister Narendra Modi.

Pakistan said the "abrupt cancellation" of talks by India and recent clashes were setback to the peace process.

It said Pakistan and India were "aware of each other's capabilities. War is not an option. It is shared responsibility of the leadership of both countries to immediately defuse the situation."

An Indian security official said Pakistani troops used small arms and mortars late Thursday to target the Hiranagar sector in Indian-held Kashmir. The official said the intensity of the shelling was less than previous days.

The top Indian administrative official in the region, who goes by the name of Shantmanu, said that Pakistani fire wounded at least 10 civilians overnight. He said 90 people, including six border guards, were wounded since Sunday and that the fighting displaced some 50,000 Indian villagers.

But security officials on both sides confirmed that a lull had set in on Friday. They spoke on condition of anonymity because they were not authorized to talk to media.

Pakistani Foreign Ministry spokeswoman Tasnim Aslam told reporters that Pakistan was "exercising great care to avoid civilian casualties" and insisted Islamabad did not escalate the situation.

"Our response has been strong and measured," she said. "Fire is returned from where it comes."

Pakistan and India have a history of tense relations and fought two of their three major wars over Kashmir, a mountainous Himalayan region with a Muslim majority. Both sides claim the territory in its entirety.

While the Line of Control is guarded by both the Pakistani and Indian armies, each country uses a separate paramilitary border force to guard the lower-altitude frontier, which is marked by coils of razor wire that snake across foothills past ancient villages and fields of rice and corn.

India accuses Pakistan of training and arming insurgent groups which have been fighting for Kashmir's merger with Pakistan or its independence since 1989. Pakistan denies the allegations.